The defense attorney for D.C. Council member Marion Barry said yesterday that he is meeting with the former mayor this week to decide how best to respond to a recent request by federal prosecutors to revoke Mr. Barry’s probation in a criminal tax case.

If the motion is granted, the revocation could put Mr. Barry back behind bars more than 15 years after he served six months on drug charges.

“Just because they write it doesn’t mean it’s true,” attorney Frederick D. Cooke Jr. said of the court filing last week in which prosecutors stated that Mr. Barry had failed to pay his 2005 taxes.

Mr. Barry received three years of probation last year after pleading guilty to failing to file returns on more than $500,000 in income from 1999 to 2004.

“I haven’t had a chance to draft a response because I have to talk to my client and gather information,” Mr. Cooke said.

In exchange for the guilty plea, prosecutors last year agreed to take no position on Mr. Barry’s request for probation at his sentencing last year.

Now, prosecutors say, Mr. Barry hasn’t lived up to his end of the deal.

In addition to failing to pay D.C. or federal income taxes in 2005, Mr. Barry also hasn’t made plans to pay off prior years’ tax debt stemming from the criminal tax case, the government memo states.

Mr. Barry’s office did not return phone calls yesterday.

Former U.S. Attorney Joseph diGenova said yesterday that Mr. Barry almost certainly will be called to testify about whether he failed to pay his taxes.

Mr. diGenova said the government’s latest request isn’t out of the ordinary.

“It would be standard practice for the government to file such a pleading when someone had failed to comply with the terms of their probation,” he said. “The courts expect the government to do this when they come into possession of knowledge that a court order, which is what probation is, has been violated.”

It will be up to U.S. Magistrate Judge Deborah A. Robinson to decide whether to revoke Mr. Barry’s probation.

“This is an elected public official, who has a higher duty of compliance than an ordinary citizen,” Mr. diGenova said.

Prosecutors argued in their memo last week that Mr. Barry has shown “unworthiness to reap the benefits of a lenient sanction.”

The prosecutors also called his failure to pay his taxes the latest in a series of “willful acts in defiance of the tax laws.” They said Mr. Barry’s actions violate his probation.

Mr. Barry had asked the Internal Revenue Service for an extension to allow him to file his return by Oct. 15, according to court records. However, no return had been filed as of last week, according to an affidavit submitted by an IRS special agent.

“The court’s patience should be at an end,” the prosecutors wrote. “A longtime elected official who has been responsible for spending public funds collected from District of Columbia taxpayers, the defendant chose not to file his own return for six years.”